Friday, November 28, 2014

The following will likely only be of interest to older runners,walkers, cyclists and folks who like to talk about mitochondria.see here for a interesting commentary about muscular efficiency,aging and its effect of various kinds of exercise.

The mainstream current party line regarding the determinants of endurance exercise performance is that the major three factors are:

1Maximum oxygen uptake ( V02Max)there are conflicting data regarding whether regular endurance training over the years lessens that decrease with the older data supporting that idea.More recently Tanaka and others have shown that when expressed as per cent decrease from early adulthood, the rate of decline in VO2Max is not reduced in habitual aerobic exercisers.See page 58 reference no. 1.

2)Lactate threshold (LT).LT as a measure of the exercise intensity at which a person can sustain a high level of the maximal oxygen consumption.It is said to decrease with aging.Although data indicate that the absolute work rate or running speed at the LT decreases as a function of age, the LT does not change when expressed as a percentage of the 02 Max. Tanakia and Seals (ref 1) suggest that the decrease in LT is secondary to decreases in the 02Max.

3)Exercise economy .This is measured as the steady-state 02 consumption while exercising below the LT.A number of cross-sectional studies have shown that exercise economy does not change with aging.Most of the studies were done in runners but now we have a study that demonstrates a decrease in excise efficiency in cyclists with aging.

Alex Hutchson in his Runner's World column,"Sweat Science", discussed several articles that demonstrated that older cyclists became less efficient with age but that deficit compared to the younger cyclists was abolished by a several week period of quadriceps resistance exercises . In one study a 3 week training period increased leg strength by about 18% and cycling efficiency by about 16%. Possibly the old high school coach's comment "you are only as young as your legs might really be "you are only as old as your quads".Aging runners and cyclists can profit by adding quad resistance exercises to their exercise program.

As early as the 1980s there was experimental evidence that resistance exercise could increase mitochondrial bio-genesis and improve oxidative capacity even in a person habitually doing endurance exercise.

Friday, November 14, 2014

The Annual Survey of Football Injuries 1931-2013 (first author Kristen Kucera) was published in March 2014.See here for the full report.

The report distinguishes between direct death (basically brain or neck injury) and indirect death which includes a cardiac cause or heat stroke among others.

In 2013, there was 8 directs deaths ,all in high school, and nine indirect deaths seven of which were related to high school football. Of the direct deaths 6 were from brain injury and 2 were from neck injuries.There are approximately 1.1 million participants in high school football. So there were 16 death related to football in 2013 in that population.News report indicate that there have been 8 apparent direct deaths from high school football in 2014 .

Of the 8 direct deaths in 2013, 3 occurred in running backs, 2 in defensive backs and one in wide receiver and one in line backer and the position of the eighth player was not known.

In 1976, a major football rule change was put into place and review of the deaths tabulated by year indicates it was an important contributor to overall fewer deaths from head and neck injury but has certainty not eliminated them There were further rule changes in 2005 and 2007 designed to eliminate the use of the helmet as a weapon.. In 1976 it became illegal to make initial contact with head and face while blocking or tackling (so called "spearing").The decrease in cervical spine injuries is greater than that seen in fatal head trauma following that rule change and the increased emphasis of not hitting with the helmet.Still from 2003 through 2013, 23 high school players died from head or neck injuries and 103 died from indirect causes ( largely heat stroke and cardiac causes).

What is thought to be the mechanism(s) involved in the football related. fatal brain injuries . The likely candidates are 1)acute subdural hematoma and 2)and those of the second hit syndrome. See here for Dr. Robert Cantu's description of ten cases of the second hit syndrome.The second hit syndrome is thought to be at least in part a disorder of cerebral blood flow auto regulation occurring acutely after a second blow to the head in a player who is still symptomatic from an earlier (perhaps unrecognized) concussion and may result in fatal herniation and brain stem compression which can occur within a few minutes of the second head blow.

Better helmets,greater awareness of concussion and the efforts to restrict play for a concussed athlete and rule changes since 1976 are thought to have decreased fatal had and neck injuries. Things did look like they have gotten better. From 1968 through 1971, 44 high school players died from head and neck injuries and 12 died in sandlot type football and 12 died playing college ball and 2 died in pro and semi pro leagues.In that 4 year time frame 70 people died from playing football .

The reports states that data from the decade 1985 - 1994 showed reduction in those injuries.However, the data from 1995-2004 show an increase in brain fatalities over that in 1985-1994 ,namely 11 more deaths during 1995-2004 representing a 33% increase.In the latest nine year period analyzed (2005-2013) 25 brain deaths have been recorded in high school players.

Football continues to be a sport in which there are high impact collisions which place the head and neck at a non trivial risk. It may be that the mitigating factors mentioned above (rule changes etc) have done what they can do but a very troublesome residual exists and young athletes continue to die while cheerleaders and family members gather on Friday nights to celebrate the rituals of high school football. Judo has been made mandatory part of high school education in Japan and a number of athletes die every year as a result of head trauma associated with that sport. Understandably parents in Japan have raised justified protests.Just imagine what protests would be raised if high school football were a mandatory part of high school education.

It has become common ( mandatory?) for an ambulance to be on hand at high school football games.I wonder if their presence is reassuring to parents or a troublesome reminder that medical tragedies continue to occur in spite of the considerable effort that has been made to avoid them.

Monday, November 10, 2014

Margalit Gur-Arie has hit another out of the park on her blog "Health Care Technology". Everyone should read her recent entry entitled "Technology for Onesies-Twosies". See Here.

Her comments are aimed at the almost one half of U.S. physicians who are still in private practice, most of which are in medium or smaller groups.The topic isthe government program to "help"private docs obtain and use electronic health records (EHRs) and its "Meaningful Use" Program which is a carrot and stick approach to get recalcitrant physicians on the program.

Quote:

"Case in point: Meaningful Use is a voluntary program. The maximum
incentive per Medicare physician is equivalent to seeing one more
patient per week. The maximum penalty for a typical Medicare physician
can be recuperated by seeing one more patient per week. The cost of
using a Meaningful Use EHR, in both cash and physician time, far exceeds
one weekly visit. Can someone please enlighten me on why there is no
market (and trust me, there isn’t) for non-government sanctioned
technology that is purposely built to serve doctors? Remember, you own
more than half the market."

Bottom line- signing on to the government subsidy EHR program is not just a bad idea it is much worse than that. Note, the computer programs that are government sanctioned are for the most part not meant to help the physician practice medicine nor to help the patient receive better care.Read her entire article and find out who really benefits.Spoiler- it ain't the patients and physicians.